US3901263A - Regulating valve for fuel metering device, especially for the combustion chamber of an aerojet engine - Google Patents

Regulating valve for fuel metering device, especially for the combustion chamber of an aerojet engine Download PDF

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Publication number
US3901263A
US3901263A US351845A US35184573A US3901263A US 3901263 A US3901263 A US 3901263A US 351845 A US351845 A US 351845A US 35184573 A US35184573 A US 35184573A US 3901263 A US3901263 A US 3901263A
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US
United States
Prior art keywords
fuel
needle
valve seat
control
shaft
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US351845A
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English (en)
Inventor
Wilhelm Grunert
Claude Gustave Gaudas
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Safran Aircraft Engines SAS
Original Assignee
SNECMA SAS
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Filing date
Publication date
Application filed by SNECMA SAS filed Critical SNECMA SAS
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Publication of US3901263A publication Critical patent/US3901263A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02C—GAS-TURBINE PLANTS; AIR INTAKES FOR JET-PROPULSION PLANTS; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS
    • F02C9/00—Controlling gas-turbine plants; Controlling fuel supply in air- breathing jet-propulsion plants
    • F02C9/26—Control of fuel supply
    • F02C9/40—Control of fuel supply specially adapted to the use of a special fuel or a plurality of fuels
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T137/00—Fluid handling
    • Y10T137/2496—Self-proportioning or correlating systems
    • Y10T137/2559—Self-controlled branched flow systems
    • Y10T137/2574—Bypass or relief controlled by main line fluid condition
    • Y10T137/2579—Flow rate responsive
    • Y10T137/2594—Choke

Definitions

  • a regulating valve comprises an obturator which moves axially so as to control the cross-sectional area of a passage connecting a return duct with a ducting system, supplying a metering device with fuel under pressure and containing or liable to contain solid impurities.
  • the obturator is a hollow needle slidably mounted on a shaft and operated by a bellows which is immersed externally in the fuel and has its interior in communication with the inside cavity of the needle and exposed to the pressure of a control fluid consisting of filtered fuel.
  • Regulatingvalves generally comprise a sliding piston which is in contact with fuel bled upstream of the metering device and which is operated by the pressure of this fuel to open and close a passage to the return dueting system.
  • the fuel delivered by the pump is often polluted, i.e. often contains solid impurities such as particles of metal, and known regulating valves have the drawback of comprising sliding surfaces which risk becoming clogged or even jammed by these impurities.
  • the present invention eliminates this drawback by causing the sliding surfaces to be bathed in filtered fuel.
  • the cross-sectional area to the return is controlled to this end by a hollow needle slidably mounted on a shaft and operated by a bellows which is bathed externally in polluted fuel and has its interior in free communication with the internal cavity of the needle, and exposed in use to the pressure of a control fluid constituted by filtered fuel.
  • the filtered fuel thus bathes the sliding surfaces of the needle and the shaft in such a manner that the latter does not risk being jammed by the impurities which may be found in the unfiltered fuel, the by-passed return flow of which is controlled by the needle.
  • the drawing is a partial sectional view of an aero-turbojet engine fuel control unit comprising a regulating valve in accordance with the invention.
  • the fuel control unit part of which is shown in the drawing, is intended to control the supply flow in a duct 1 linked to the injectors, not illustrated, of the combustion chamber of the jet engine, of fuel bled at 2 by the fuel pump 3.
  • the polluted fuel i.e. containingor liable to contain solid impurities
  • the pump delivers the fuel via inlets 3a, 3b to two ducts 4a, 4b flowing into a ducting system 4 terminating at the inlet 5 to a metering device, which is designated as a whole by the reference 6.
  • the delivery duct 4a comprises a section the wall of which consists of a porous sleeve 7a and which is enclosed in a chamber 7b forming, together with the sleeve '70, a filter 7 according to theinvention.
  • a duct 8 which thus receives fuel from the duct 4a through the sleeve 7a and consequently filtered, and which supplies devices which will be described later.
  • These devices consume a very small amount of fuel; moreover, the filtering sleeve 7a' does not risk becomng Clogged since, as has already been stated, its entry surface is permanently washed by the fuel circulating at a high rate in the duct 4a, so that the pressure loss undergone by the fuel when passing through the filter is negligable and the pressure obtaining in the duct 8 is almost equal to the pressure in the channel 4.
  • the metering device 6 comprises a needle 9 provided with a cylindrical shaft 9a which slides in a bore 10 under the action of a control device 11, which will be briefly described later on, in such a way as to modify in opposite direction the cross sectional areas of two apertures 12 and 13 respectively providing communication between the inlet 5 of the metering device and its outlet 14 and with a chamber 15 which communicates with a return fuel channel 16 which by-passes the pump 3.
  • the outlet 14 of the metering device opens into a duct 17 which can be made to communicate with I the duct 1 in order to supply the injectors by a poppet valve device, represented as a whole by the reference 18, which does not form part of the present invention.
  • this poppet valve device 18 can be controlled manually by means of a three-way cock 1Q which allows a control chamber 18a of this device to communicate with either the duct 8 or the chamber 15. Closing of this poppet valve device places the duct 1 in communication with a drain duct 18b.
  • the ducting system 4 supplying the metering device 6 from the pump 3 is also linked by a regulating valve or obdurator 20 to a.fuel return duct 21 which bypasses the pump.
  • This regulating valve 20 more or less opens communication between the ducting system 4 and the duct 21 in such a way as to maintain constant the pressure differential Ap between the inlet 5 and the outlet 14 of metering device 6.
  • the regulating valve 20 is arranged according to the invention. It comprises a needle 22 moving axially within a cavity forming two inlet chambers 23, 24 on either side of a central outlet chamber 25 with which they can be made to communicate, respectively, by two annular apertures 23a, 24a contained between the needle and two circular seats 23b, 24b.
  • the needle is provided with a blind axial bore26 containing bearings 26a, 26b by which it is slidably mounted on a shaft 27 fixed at the bottom of the chamber 24.
  • the inlet of the bore 26 is counterbored in steps so as to form a shoulder 28a against which bears a spring 28 which rests on the bottom of the chamber 24, and it is provided with a flange 29a to which is welded one end of a bellows 29 of which the other end is secured in a sealed manner to the bottom of the chamber 24.
  • the two inlet chambers 23, 24 are linked to the ducting system 4, respectively by ducts 23c and 24c, and the outlet chamber 25 is linked with the return duct 21.
  • the external surface portions of the needle 22 which respectively cooperate with the seats 23b and 24b are truncated cones, the major bases of which are in the direction of the bellows 29, so that by making the needle slide in the direction of the bellows, the cross sectional area of the two annular apertures 23a and 24a is enlarged and consequently the amount of fuel flowing from the ducting system 4 into the return duct 21 is increased. Conversely, displacing the needle in the opposite direction progressively reduces this quantity to nil.
  • the displacement of needle 22 is controlled by filtered fuel filling the bore 26 and the interior of the bellows 2%, the pressure of which is modulated by an apparatus 30 called a Ap (or pressure differential) detector.
  • the fuel is bled from the ducting system 4 through a filter 31 analogous to the filter 7 by a duct 32 comprising, below a restrictor 32a, passage 32b which opens through the shaft 27 into the bellows 29 and a branching 32c which ends at a nozzle 33 opening into the detector 30 facing a throttling member 30a.
  • the detector comprises a chamber 34 in which throttling member 30a moves axially under the joint effect of a bellows 35 and a spring 36.
  • the interior of the bellows 35 communicates with the ducting system 4 by a duct 35a, whilst the area of the cavity 34 located outside this bellows communicates by a duct 34a with the duct 17 where controlled fuel is flowing downstream of the metering device 6.
  • the nozzle 33 thus forms with the throttling member 30a an escape device the principle of which is well known and which modulates according to Ap the pressure of filtered fuel in the duct 32 downstream of the restrictor 32a.
  • This modulated pressure applied through the passage 32b in the bellows 29 of the regulating valve 20, acts on the needle 22 in the same direction as the spring 28 and in opposition to the inlet pressure of the fuel acting on the needle 22.
  • the throttling member 30a moves away from the nozzle 33 and thus causes a reduction in the modulated pressure acting in the bellows 29, so that the needle 22 is displaced in the direction of this bellows and increases the cross-sectional area of the apertures 23a and 24a; the escape of fuel from the ducting system 4 towards the return duct 21 therefore increases, so that the pressure in the ducting system 4 falls and equilibrium is reestablished.
  • the filtered fuel which fills the interior of the needle 22 and of the bellows 29 is not in contact with polluted, i.e., unfiltered, fuel, so that the displacement of the needle takes place without risk of jamming and with the filtered fuel lubricating the bearings 26a, 26b which ensures a frictionless movement.
  • the filter 31, the same as the filter 7 and for the same reason, does not run the risk of getting clogged and thus disturbing the modulated pressure which operates the regulating valve.
  • the two seats 23b, 24b have the same diameter and the shape of the truncated conical surface of needle 22 with which they work can easily be calculated in order that the reactions brought about by the two flows from chambers 23, 24 towards central chamber 25 may compensate for one another.
  • the fuel control unit described functions as a whole in the following way.
  • the poppet valve device 18 is opened when the engine is started and is closed only when it is stopped; it stays open throughout the period of operation and the metering device 6 regulates the flow of fuel which is supplied to the injectors, not illustrated, through ducts 17 and 1.
  • the active part of the needle 9 comprises two portions with the surface inclined in opposite directions 12a, 13a, having approximately the shape of two truncated cones joined side by side at their large base, which regulate respectively the cross sectional areas of the annular aperture 12 allowing passage to the metered flow and of the annular passage 13 through which the surplus flow entering the metering device at is discharged into cavity 15 and from there into the return duct 16.
  • the pressure differential Ap undergone by the fuel when passing through the regulating annular aperture 12 is kept constant by the regulating valve 20, the flow passing through this aperture 12 is maintained proportional to the cross sectional area of the latter.
  • the control device 11 of the metering device comprises a cylinder 37 in which slides a piston 38 integral with a shaft 9a of the needle 9.
  • a by-pass 39 of the filtered fuel duct 8 feeds, respectively through throttles 39a and 39b, the two chambers of the cylinder separated by the piston 38.
  • the pressures in these two chambers are modulated, according to the various regulation parameters of the engine, by an apparatus 40 called a force balance, which does not form part of the invention and need not be described in detail.
  • this partition 41 there is an annular groove 43 communicating with duct 8.
  • the pressure of thhe filtered fuel in the duct 8 is almost equal to the pressure of the ducting system 4, which is higher by the quantity Ap than the pressure of the chamber 42.
  • the filtered fuel therefore tends to flow from the annular grove 43 towards the chamber 42 and prevents the impurities contained in the unfiltered fuel circulating in this chamber from penetrating into the gap between the shaft 9a and the bore 10, so that there is no risk of this shaft jamming in this bore. Neither is there a risk of piston 38 jamming, since the fuel filling the cylinder 37 is filtered.
  • a regularing valve for by-passing part of said unfiltered fuel from said intake ducting means to a fuel return duct to I control said intake pressure and comprising a valve housing having inlet and outlet chambers and means defining an orifice therebetween, piping means for delivering unfiltered fuel from said intake ducting means to said inlet chamber and from said outlet chamber to said fuel return duct, a throttling needle having an internal cavity therein and a tapering outer surface and extending in said inlet and outlet chambers through said orifice to devine an annular passage therebetween, a stationary shaft coaxial with the needle and projecting within the internal cavity in said needle, guiding means in the internal cavity to guide
  • a regulating valve as claimed in claim 1 in which the internal cavity of the needed is a blind bore.
  • control means comprise duct means connecting the intake ducting means to the control chamber, a filter in the duct means, a restriction in the duct means between the filter and the control chamber, and an escape device for controlling a leakage of filtered fuel downstream of the restriction, in response to the pressure differential.
  • deformable partition means comprise a bellows arranged around the shaft and having one end fixed to the needle and one end fixed to the valve housing.
  • a regulating valve for by-passing part of said unfiltered fuel from the feed ducting means to a fuel return duct comprising a valve housing, a valve seat in said valve housing, piping means for connecting the valve seat between the feed ducting means and the return duct to supply the valve seat and return duct with a by-pass flow of unfiltered fuel, a needle having an internal cavity therein ahd projecting through the valve seat to define a passage therebetween a stationary shaft coaxial with the needle and projecting within the internal cavity, guiding means in the internal cavity to guide the needle for axial movement along the shaft, the external surface of said needle being shaped in relation to said valve seat to vary the cross-sectional area of the passage when said needle is moved axially,

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Fuel-Injection Apparatus (AREA)
US351845A 1972-04-18 1973-04-17 Regulating valve for fuel metering device, especially for the combustion chamber of an aerojet engine Expired - Lifetime US3901263A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR7213606A FR2180485B1 (de) 1972-04-18 1972-04-18

Publications (1)

Publication Number Publication Date
US3901263A true US3901263A (en) 1975-08-26

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Family Applications (1)

Application Number Title Priority Date Filing Date
US351845A Expired - Lifetime US3901263A (en) 1972-04-18 1973-04-17 Regulating valve for fuel metering device, especially for the combustion chamber of an aerojet engine

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US (1) US3901263A (de)
DE (1) DE2319762C3 (de)
FR (1) FR2180485B1 (de)
GB (1) GB1421010A (de)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5501245A (en) * 1993-10-20 1996-03-26 Societe Nationale D'etude Et De Construction De Moteurs D'aviation (S.N.E.C.M.A.) Coaxial pressurized fluid flow regulator

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2528495B1 (fr) * 1982-06-09 1987-01-16 Snecma Ensemble de regulation a doseur de debit et soupape regulatrice
DE3374089D1 (en) * 1983-06-02 1987-11-19 Snecma Flow control device with integrated pressure detector
US4502501A (en) * 1983-06-14 1985-03-05 S.N.E.C.M.A. Fuel control assembly incorporating an integral pressure drop monitor for use with a gas turbine plant
DE3521193A1 (de) * 1985-06-13 1986-12-18 MTU Motoren- und Turbinen-Union München GmbH, 8000 München Brennstoffsteuereinrichtung eines gasturbinentriebwerks mit einem kombinierten druckaufbau-, drainage- und absperrventil
FR2594488B1 (fr) * 1986-02-19 1988-05-06 Snecma Amelioration aux regulateurs hydromecaniques
JP4315109B2 (ja) 2005-02-16 2009-08-19 株式会社デンソー ポンプ装置
AU2008337508B2 (en) 2007-12-17 2012-03-15 Technocell Dekor Gmbh & Co. Kg Compressible decorative paper impregnating agent which can be printed by the inkjet method

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US895342A (en) * 1907-08-17 1908-08-04 George W Collin Boiler feed-valve.
US1925301A (en) * 1933-09-05 Valve
US3179293A (en) * 1962-10-18 1965-04-20 Donald G Griswold Tank filling valve
US3799498A (en) * 1971-03-05 1974-03-26 Westinghouse Brake & Signal Valve means

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1925301A (en) * 1933-09-05 Valve
US895342A (en) * 1907-08-17 1908-08-04 George W Collin Boiler feed-valve.
US3179293A (en) * 1962-10-18 1965-04-20 Donald G Griswold Tank filling valve
US3799498A (en) * 1971-03-05 1974-03-26 Westinghouse Brake & Signal Valve means

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5501245A (en) * 1993-10-20 1996-03-26 Societe Nationale D'etude Et De Construction De Moteurs D'aviation (S.N.E.C.M.A.) Coaxial pressurized fluid flow regulator

Also Published As

Publication number Publication date
DE2319762C3 (de) 1979-01-18
DE2319762A1 (de) 1973-10-31
DE2319762B2 (de) 1978-05-24
GB1421010A (en) 1976-01-14
FR2180485B1 (de) 1976-06-11
FR2180485A1 (de) 1973-11-30

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